Robust Image Watermarking Based on SIFT Feature and Optimal Triangulation

An image watermarking scheme resistant to rotation scale translation (RST) attacks is proposed based on scale invariant feature transform (SIFT). Suitable feature points are selected to form a convex hull, which is then optimally triangulated by dynamic programming. The triangle chords inside the hull are then sampled equispacedly with secrect key K to obtain smaller triangles. The watermark is then embedded into the the circles centering around the centeroid of each triangle. The experiments show that the proposed method is considerably robust against both geometric distortion attacks and signal processing attacks.